SIDS (sudden infant death syndrome)

Sudden Infant Death Syndrome (SIDS) is the sudden and unexpected death of a child during sleep under one year of age. It usually occurs in what appears to be a perfectly healthy child. The risk is highest between
2-4 months of age with about 95% of the cases occurring before 6 months of age.  Research shows that around 97% of babies that die of SIDS have at least one known risk factors and around 80% of babies have at least two knows risk factors. After years of research scientist still don't know exactly what causes SIDS (there are many guesses out there though) although they have found some things that seem to reduce it.

Information regarding SIDS can change at anytime so I suggest you always make sure you know the most up to date information since the information I have listed might be out of date (although I'll do my best to keep it up to date). Your pediatrician is a good resource for the most up to date information. I have also listed some resources below that include additional information I have not listed here.

SIDS Safety Recommendations:

• Foremost, have your baby sleep on his back. Babies who sleep on their stomach are at least three times more likely to die of SIDS, variables aside (webmd.com). I sometimes hear people say that they slept on their stomach or some of their children slept on their stomach without problems so they feel fine about it. But keep in mind that regardless of who you know that has slept safely on his stomach as a baby, your chances of having a baby die of SIDS by sleeping on his stomach is still the same. Note that for some babies it is better for them to sleep on their stomach but this should be done under the supervision of your pediatrician. Also, for those of you who still have your babies sleep on their stomachs, I suggest you use some kind of movement monitor. Some other possible benefits of back sleeping include fewer ear infections, stuffy noses and fevers. 
• Keep the bed clear of blankets, pillows etc. If you are worried baby might be cold, put on extra clothing instead of using blankets. See sleep attire for some SIDS friendly sleepers. Once baby is over four months old and can roll over and move his head easily Pantley says you can introduce a safe lovey.
• Do not smoke around baby.
• Crib mattress needs to fit snugly and be firm and flat. As nice as a family heirloom may be, it may not be safe. My mother in law actually gave us the bassinet that all her children used when our son Joshua was born. Being over 40 years old, it was far from safe. We actually had our son sleep in it a couple times while we sat next to him just so we could tell her we used it. She was so excited to give it to us that we didn't want to hurt her feelings by not ever using it. I guess we could have lied, but seeing as I'm horrible at lying it wouldn't have worked out so well. I suppose that is a good thing, but it can be really annoying sometimes! You can look here for crib guidelines.
• Don't keep baby too warm. Hats especially can lead to overheating. Usually a temperature between 65-72 degrees Fahrenheit is appropriate.
• Breast feeding may reduce the risk.
• Choking on vomit has not been shown to be a problem with SIDS. Babies have been shows to shallow what comes up or move their head to the side to let it fall out. If I'm remembering right, I found this in Ferber's book. This may sounds like a really bizarre thing to include here, but there are some babies that easily vomit from any amount of crying and others that often spit up after eating so this could be a concern for some parents.
• When babies learn to turn both ways by themselves and have good head control the risk of SIDS is very low. Most pediatricians tell patients that it is OK for baby to sleep on his stomach once he can roll easily. This may not be the case with your pediatrician so I would definitely check first.
• Using a pacifier may decrease risk of SIDS although there is not strong evidence for this yet. This could be due to increased awakenings with pacifier babies or because pacifiers keep mouth clear of bedding etc.
• Turning a fan on in your baby's room during sleep time may decrease SIDS risk.

Some risk factors that increase the risk of SIDS: 

• nonexistent prenatal care
• prematurity
• low birth weight.

Useful sources to find information about SIDS:
http://www.sids.org/nprevent.htm
http://www.nichd.nih.gov/sids/
U.S. Public Health Service
American Academy of Pediatrics
SIDS Alliance
Association of SIDS and Infant Mortality Programs
SIDS Back to Sleep Campaign